165918985 has 8 divisors (see below), whose sum is σ = 201155976. Its totient is φ = 131366400.

The previous prime is 165918953. The next prime is 165919007. The reversal of 165918985 is 589819561.

165918985 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 18636489 + 147282496 = 4317^2 + 12136^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 165918985 - 2⁵ = 165918953 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 170566 + ... + 171535.

It is an arithmetic number, because the mean of its divisors is an integer number (25144497).

Almost surely, 2^165918985 is an apocalyptic number.

It is an amenable number.

165918985 is a deficient number, since it is larger than the sum of its proper divisors (35236991).

165918985 is an equidigital number, since it uses as much as digits as its factorization.

165918985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342203.

The product of its digits is 777600, while the sum is 52.

The square root of 165918985 is about 12880.9543512893. The cubic root of 165918985 is about 549.4970443372.

The spelling of 165918985 in words is "one hundred sixty-five million, nine hundred eighteen thousand, nine hundred eighty-five".